Belegost and Nogrod were the two great dwarf cities in the Ered Luin, known as Gabilgathol and Tumunzahar in their native tongue.

Both cities lay beneath the central Ered Luin, close to Mount Dolmed. The great Dwarf Road ran from this area down into Beleriand where the dwarves and elves enjoyed mutual trade.

The friendship ended abruptly after a dispute between Thingol and the dwarves of Nogrod over the Nauglamir and its Silmaril, which led to the death of Thingol and the sack of Menegroth by the dwarves.